1. Field of the Invention
The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device and a driving method thereof, which can prevent a panel abnormality, such as short circuit, burning, or a line defect, of an organic light emitting panel from being spread.
2. Discussion of the Related Art
Flat panel display (FPD) devices are applied to various electronic devices such as portable phones, tablet personal computers (PCs), notebook computers, etc. The FPD devices include liquid crystal display (LCD) devices, plasma display panel (PDP) devices, light-emitting display devices, etc. Recently, electrophoretic display (EPD) devices are widely used as the FPD devices.
In such FPD devices, the light emitting display devices have a fast response time of 1 ms or less and low power consumption, and have no limitation in a viewing angle because the light emitting display devices self-emit light. Accordingly, the light emitting display devices are attracting much attention as next generation FPD devices.
Generally, the light emitting display devices are display devices that electrically excite a light emitting material to emit light, and are categorized into inorganic light emitting display devices and organic light emitting display devices depending on a material and a structure thereof.
FIG. 1 is a circuit diagram schematically illustrating a pixel circuit of a general organic light emitting display device.
A plurality of pixels, which are respectively formed in a plurality of areas defined by intersections between a plurality of gate lines and a plurality of data lines, are formed in a panel of the organic light emitting display device. A pixel circuit is formed in each of the plurality of pixels.
The pixel circuit, as illustrated in FIG. 1, includes a switching transistor ST, a driving transistor DT, a capacitor C, and a light emitting element OLED.
The switching transistor ST is turned on by a scan signal supplied to a gate line GL, and supplies a data voltage Vdata, supplied from a data line DL, to the driving transistor DT.
The driving transistor DT is turned on with the data voltage Vdata supplied from the switching transistor ST, and controls a data current Ioled which flows from a high-level driving voltage ELVDD terminal to the light emitting element OLED.
The capacitor C is connected to a gate of the driving transistor DT, stores a voltage corresponding to the data voltage Vdata supplied to the gate of the driving transistor DT, and turns on the driving transistor DT with the stored voltage.
The light emitting element OLED is electrically connected between the driving transistor DT and a low-level driving voltage ELVSS terminal (a ground terminal), and emits light with the data current Ioled supplied from the driving transistor DT. Here, the data current Ioled flowing in the light emitting element OLED is determined according to a gate-source voltage of the driving transistor DT, a threshold voltage of the driving transistor DT, and the data voltage Vdata.
The pixel circuit of the general organic light emitting display device controls a level of the data current Ioled, which flows from the high-level driving voltage ELVDD terminal to the light emitting element OLED, according to the data voltage Vdata supplied to the gate of the driving transistor DT to emit light from the light emitting element OLED, thereby displaying an image.
FIG. 2 is an exemplary diagram illustrating a configuration of a general organic light emitting display device.
The general organic light emitting display device, as illustrated in FIG. 2, includes: a panel 10 in which a plurality of pixels are respectively formed in a plurality of areas defined by intersections between a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm; a gate driving integrated circuit (IC) 20 that supplies a scan signal to the plurality of gate lines; a source driving IC 30 that respectively supplies data voltages to the plurality of data lines; a timing controller 40 that controls driving of the gate driving IC 20 and driving of the source driving IC 30; and a power supply 50 that supplies a high-level driving voltage ELVDD and a low-level driving voltage ELVSS to the plurality of pixels.
In the general organic light emitting display device, as illustrated in FIG. 2, a high-level driving voltage ELVDD line 51 and a low-level driving voltage ELVSS line 52 are disposed in an upper inactive area and a lower inactive area, and the data lines DL1 to DLm extend from the source driving IC 30 to overlap the high-level driving voltage ELVDD line 51 and the low-level driving voltage ELVSS line 52.
In addition to the high-level driving voltage ELVDD line 51 and the low-level driving voltage ELVSS line 52, various power lines such as a reference voltage Vref line are formed to overlap the data lines.
An organic layer covering the lines is damaged by various causes, or when short circuit between the lines occurs, defects such as burning and a line defect can occur.
In order to prevent defects such as short circuit, burning, and a line defect, in the related art, short circuit or burning is detected through a guide ring that is formed outside an active area 12, namely, in the inactive area.
However, in the related art, short circuit, burning, or a line defect is detected in only the inactive area, and thus, even when a failure is caused by short circuit, burning, or a line defect which occurs in the active area 12, it is unable to appropriately respond to the failure.
The above-described overlapping section is formed in the active area 12 as well as the inactive area, and particularly, power lines such as the high-level driving voltage ELVDD line 51, the low-level driving voltage ELVSS line 52, the reference voltage Vref line (not shown), and the data line DL overlap the gate lines GL in various types in the active area 12.
Therefore, when the organic layer insulating the lines is damaged by a crack or the like, there is a high possibility that short circuit occurs between the lines. When the short circuit occurs, a current flows through the lines, and thus, there is a high possibility that burning occurs in the gate driving IC 20 or the panel 10.
However, as described above, in the related art, since a sensing line for detecting short circuit, burning, or a line defect in the active area 12 is not provided, it is unable to appropriately respond to the short circuit, the burning, or the line defect in the active area 12.
Moreover, a method in which an additional detection line is formed in the active area 12 is proposed for detecting the short circuit, burning, or line defect of the overlapping section in the active area 12. However, in organic light emitting display devices using the method, an aperture ratio of the active area is reduced, and the overlapping section increases, causing the other problems.